Ion-Containing Block Copolymers for Efficient Capture of a Chemotherapy Drug

Ion-containing polymer membranes are widely used in clean-water-related technologies (e.g., desalination, eletrodialysis), power generation (e.g., forward osmosis, fuel cells, batteries), and bioengineering (hemodialysis, drug delivery, controlled release). For biomedical applications, previous literature has focused on polymers used for drug delivery and controlled release. Sophisticated polymer design is required for biomedical applications since the drugs must remain in a carrier polymer until the target locates near the drug, and severe side-effects must not occur during this process, as a carrier polymer makes its way through the body.

In this work, we study ion-containing polymers for an emerging application that we call “drug capture”. These polymers are incorporated in a new class of biomedical devices that we call “ChemoFilter”, in order to increase the effectiveness of chemotherapy based cancer treatment. In this approach, the drug is injected at the target organ’s artery­­. After the drug passes the target organ, it is captured by a polymer membrane placed at the exiting vein from the target organ using minimally invasive surgical methods (similar to approaches for introducing stents in patients having heart diseases). The goal is to capture all of the drug exiting the target organ using ion-containing polymer membranes, and the ChemoFilter is removed at the end of treatment.

Herein, we have prepared robust, ion-containing block copolymer membranes using a polystyrenesulfonate-block-polyethylene-block-polystyrenesulfonate (S-SES) triblock copolymer to remove a chemotherapy drug, Doxorubicin, from the blood stream. Doxorubicin is currently widely used in treating liver cancer, however, the current treatment is limited by adverse side-effects due to the interaction between the unused drug molecules and the human tissue. The goal is to remove most (>90%) of the drug in less than an hour to reduce toxic side-effects. The ion-containing polystyrenesulfonate microphase captures the drug, and the hydrophobic polyethylene microphase gives mechanical strength for the membrane.

In order to maximize the drug binding capabilities and fast binding kinetics of polymer membranes, we have systematically changed sulfonation level, block composition, and post-synthesis treatments in the polymer membranes, and this approach enables the tuning of polymer morphology. In this talk, the relationship between polymer morphology and the efficacy of the drug capture will be discussed.